Centerless grinding gage



June 26, 1956 s. A. FosTER CENTERLESS GRINDING GAGE 2 Sheets-Sheet 1 Filed Feb. 26, 1954 June 26, 1956 s. A. FOSTER 2,751,720

CENTERLESS GRINDING GAGE Filed Feb. 26, 1954 2 Sheets-Sheet 2 United States Patent CENTERLESS GRINDING GAGE Shubel A. Foster, Birmingham, Mich., assignor to Foster Engineering Corporation, Royal Oak, Mich., a corporation of Michigan This invention relates to the provision of means for the gaging of the progress of grinding cylindrical work in a centerless-grinding machine wherein the work is supported, on a rest blade, between two opposed grinding wheels; all of which have the effect of so limiting access to the work, as by those types of continuous checking gages such as have been generally available on the market, that such continuous gaging of the diameter of the work in a centerless-grinding machine has been heretofore considered impractical.

It has been long a common practice to continuously gage cylindrical work while being ground in a chuck or between centers so that mere observance of a dial indicator, or of other indicating means, would not only inform the operator as to the completion of the grinding operation but would warn him of its approaching completion; so that the modification of the grinding operation at that point might be effected by the operator if so desired.

The present invention, therefore, aims to provide a simple arrangement of gaging apparatus utilizing the rest blade of the centerless-grinding machine as a gage anvil and providing for such adjustments and positioning of a gage shoe to be biassed against the work in opposition to the work rest in a manner ensuring an accurate determination of the diameter of the work as it is reduced in the process of grinding.

Still further objects or advantages additional or subsidiary to the aforesaid objects, or resulting from the construction or operation of the invention as it may be carried into effect, will become apparent as the said invention is hereinafter further disclosed.

In carrying the said invention into efiect, I may adopt the novel construction and arrangement of parts hereinafter described, by way of example, having reference to the accompanying drawings, wherein:

Figure 1 is a fragmentary side elevation illustrating the active parts of a centerless-grinding machine showing my improved gage mounted thereon in working position;

Figure 2 is a rear elevation of the gage mounting taken on a plane indicated by the line 2-2 in Figure 1; and

Figure 3 is an enlarged detail elevation of the adjustable wear-member or shoe of the gage.

The two opposed grinding wheels and 11 common to centerless-grinding machines are shown in their relationship to cylindrical work 12 which is supported by the rest blade 13 in the well known manner. This blade is usually of quite hard material, such as Carboloy, and it is the common practice to bevel its upper face 14 at a substantial angle, usually about 15 degrees to the horizontal, in the manner shown for the most satisfactory support of the work between the grinding wheels.

Although it has long been the practice to use automatic checking gage mechanisms on cylindrical grinding, other than on centerless-grinders, to indicate the progress of grinding even to a finished stage while the grinding operaice tion is proceeding (as for example in the case of United States Patent No. 2,267,559, granted to me December 23, 1941, and No. 2,270,728, granted to me January 20, 1942) it has long been recognized that some such method of indicating the progress of the grinding in a centerlessgrinding machine would be desirable; but restrictions imposed by the presence of the opposed grinding wheels, especially on small work, have posed quite a problem which I have now successfully overcome in quite a simple and hitherto apparently unobvious manner.

Utilizing, as quite convenient for the purpose, an arrangement of a biassed gage rod coupled with a gage (such as in the manner described in my aforesaid Patent 2,270,723 or in combination with machine-controlling mechanism as described in my said Patent No. 2,267,559) I simply provide an arrangement whereby the lower terminal wear-member or shoe of this gage rod is reciprocated substantially perpendicular to the bevelled face 14 of the work rest blade 13, with provision for insuring that the working face of the said shoe may be maintained parallel with the bevelled face of the said blade 13 throughout a grinding operation.

In the illustrated example: 15 is the gage rod coaxially reciprocal within the sleeve 16, on the upper end of which sleeve is mounted a head 17 enclosing the spring 18 which urges the said gage rod 15 downwardly, as will be obvious. The upper end of this gage rod is shown as provided with an extension or finger 19 adapted to impinge the reciprocal stem 20 of a dial indicator 21 whereby gaging movements of the rod 15 may be indicated to an observer.

The sleeve 16 is shown as being clamped by the set screw 22 in a supporting member 23, which member is shown as being in the form of a bar extending transversely between the two grinding wheels and above the work. This bar terminates in trunnions 24 secured in clamping members 25, each of which members 25 is, in turn, mounted on the free end of a short shaft 26 which each have a spherical inner end 27 clamped, as by set screws 28, in the split upper ends of supporting brackets 29. These brackets 29 are attached to the machine member 30 which carries the Work rest blade 13.

It will thus be seen that, by virtue of the slidable adjustment of the gage tube 16 in the supporting member 23 and the various angular and other adjustments of this rod permitted by loosening the clamps 25 and the loosening of the split clamps at the upper ends of the members 29, the desired positioning of the gage rod relative to the work rest blade and to suit the diameter of the work to be gaged may be readily and satisfactorily effected. More particularly, the setting of the axis of the gage rod substantially perpendicular to the bevelled face of the rest blade 13 may be insured.

The lower end of the gage rod is provided with a mounting 31 secured by a set screw 32 which acts as a pivot or hinge about which the said mounting may be locked in positions of angular adjustment. This mounting carries the Wear-member or shoe 33 of the gage.

It will now be seen (as indicated by the dotted lines in Figure 1) that, after spacing the grinding wheels 10 and 11 apart to a desirable extent, preferably somewhat greater than the diameter of the work to be ground, the sleeve 16 of the gage may be adjusted as by the means described both angularly and axially to a position wherein the axis of the gage rod 15 is substantially perpendicular to the bevelled face 14 of the rest blade 13.

The gage tube 16 is also moved downwardly in its loosened support until the shoe 33 is brought into direct contact with the said bevelled surface 14 of the rest blade 13 whereupon, by loosening the set screw 31, the face of the shoe 33 may be accurately seated on the bevelled surface 14 and the shoe mounting 31 thereafter firmly secured in this position of adjustment by the tightening of the said set screw 32.

- The sleeve 16 is then raised axially in its support 23 to a point which will permit the work to be inserted between the rest blade 13 and the shoe 33 so that the adjusted face of the said shoe 33 may be resiliently biassed against the upper surface of the work by the action of the spring 18.

Means are provided for manually raising the gage rod 15 in its sleeve to permit the insertion of work in position beneath the shoe 33 (either by manual or by automatic insertion as the case. may be) and, as an example of such means, I show a bell-crank lever 34 positioned to actuate a lifter rod 35 against the underside of the gage rod extension or finger 19.

By ensuring parallelism between the bevelled face 14 of the rest blade 13 and the under surface of the gage shoe 33 an indication of the true diameter of the work at all times is rendered possible regardless of the decreasing diameter as the grinding proceeds. Therefore, it is possible by a simple observance of the dial indicator 21 to determine precisely when the grinding operation is completed or has been carried out to an extent which is required to be known.

This invention may be developed Within the scope of the following claims without departing from the essential features of the said invention, and it is desired that the specification and drawing be read as being merely illus-. trative of a practical embodiment of the same and not in a strictly limiting sense.

What I claim is:

1. In a device of the character described, a pair of oppositely spaced centerless grinding wheels, a blade located between said wheels and having a substantially fiat face for supporting a work piece, a support means adjacent said wheels and having an arm located above said blade, adjustable mounting means, on said arm, slidably and swingably supporting a sleeve, a work-contacting gage bar fitted in said sleeve, said sleeve being slidable toward or away from said blade face, said mounting means being angularly adjustable for swinging said sleeve into perpendicular alignment with said blade face and having means for fixing said sleeve in adjusted slidable position properly spaced from said blade whereby said bar may contact the surface of a work piece at a point diametrically opposite to the blade face point of contact with said work-piece.

2. In a device as set forth in claim 1 above, and including an adjustable work-contacting shoe on said bar said shoe having a face adaptable tobe fixed. in substantial parallelism with said blade face.

References Cited in the file of this patent UNITED STATES PATENTS 773,983 Reisner Nov. 1, 1904 1,299,838 Keller Apr. 8, 1919 1,768,931 Pratt July 1, 1930 2,049,611 Harrison et al. Aug. 4, 1936 2,073,509 Belden et al. Mar. 9, 1937 2,464,387 Foster Mar. 15, 1949 2,486,950 Iagen Nov. 1, 1949 FOREIGN PATENTS 366,005 Great Britain Jan. 25, 1932 

